They are also frequently spotted in cities and temple complexes. Rhesus macaques are able to survive in both cold and heat. In winter they have thicker fur. They generally live to be about 28, but some will be over thirty years old.

Physical characteristics
Rhesus macaques have reddish brown fur and much lighter-coloured bellies. Their faces are pink and bereft of fur. The females of the species may have red faces during their fertile periods. Adult animals measure up to 64 cm and have a tail measuring 18 to 30 cm. Males weigh approximately 10 kg, while females often weigh only half of that.

Behaviour
Rhesus macaques are excellent and fast climbers and also love swimming. They live in social groups comprised of eleven tot seventy animals, with the average troop being comprised of some twenty animals. Groups tend to consist mainly of females, with just a few males. Young males are raised by the entire group. They tend to leave their group at age 4 or 5. They will then fight other males to become the dominant male in another group, where they will mate and breed. Rhesus macaques are aggressive animals whose groups have a strict hierarchy.

Diet
Rhesus macaques mainly eat plant materials – generally herbs, but also leaves, needles and roots. They may also eat invertebrates or even small vertebrates or birds. Rhesus macaques have cheek pouches in which they can temporarily store food.

Reproduction
In Northern India, rhesus macaque procreation is seasonal. In warmer areas, they have young all year round. After a gestation period of 135 to 194 days, they will typically give birth to one young. Females reach sexual maturity at around three years of age, and tend to have their first young at age 4 or 5. Males are sexually mature at around age 4.

BPRC works with rhesus macaques because...
they are genetically 93% identical to humans. When it comes to the genes that are vital to the immune system, rhesus macaques' genes are an impressive 97% identical to humans'. By examining how monkeys' genes behave in certain situations, we can get a good idea of how the corresponding human genes would respond.

How rhesus macaques live at BPRC
Animals used for breeding purposes live in natural troops with the same composition as troops living in the wild. They live in large indoor and outdoor enclosures which have been equipped with climbing materials and toys. Monkeys which are being prepared for experiments receive extensive training. We use the fact that they are curious animals to familiarise them with experimental situations, always rewarding them for good behaviour.

Monkeys used for experimental purposes live in smaller enclosures, where animal care workers keep a close eye on their well-being. Monkeys never undergo experimentation alone. They are always joined by their friends and siblings. They are given many playthings, such as food jigsaw puzzles and materials that they can tear to pieces.

They live in woodlands near rivers. They live high in the treetops as well as on level ground. They are also frequently spotted in cities and temple complexes.

Physical characteristics
Crab-eating macaques have greyish brown fur and much lighter-coloured bellies. They have brown faces that are partially covered in fur. They are easily recognisable by the small tuft of hair on their heads. Adult females will sometimes grow beards. Adult animals measure up to 50 cm and have a tail measuring 50 to 60 cm. Males generally weigh 6 to 8 kg, while females often weigh only half of that.

Behaviour
Crab-eating macaques are excellent and fast climbers and love swimming. They live in social groups which are typically comprised of some thirty animals. Groups tend to consist mainly of females, with just a few males. Young monkeys are raised by the entire group. They tend to leave their group at age 4 or 5. They will then fight other males to become the dominant male in another group, where they will mate and breed. Troops are subject to a strict hierarchy.

Diet
Crab-eating macaques mainly eat fruit. In addition, they like leaves, buds, grass, flowers, seeds, insects, shrimp, frogs and, as their name suggests, crabs.

Reproduction
Crab-eating macaques mate and breed all year. Once every year or every two years they will give birth, typically to one young. Females reach sexual maturity at about age 4. Crab-eating macaques generally live to be 30-35 years of age.

BPRC works with crab-eating macaques because...
 ... animal behaviour experts study our social groups of crab-eating macaques on a daily basis. In this way, we learn much about their behaviour. Furthermore, because we are gaining a better understanding of them, we are better able to prevent them from experiencing anxiety during experiments. In addition, their behaviour teaches us more about human social behaviour. We sometimes use crab-eating macaques for biomedical experimentation purposes. How crab-eating macaques live at BPRC Animals used for breeding purposes live in natural troops with the same composition as troops living in the wild. They live in large indoor and outdoor enclosures which have been equipped with climbing materials and toys. Monkeys which are being prepared for experiments receive extensive training. We use the fact that they are curious animals to familiarise them with experimental situations, always rewarding them for good behaviour. Monkeys used for experimental purposes live in smaller enclosures, where animal care workers keep a close eye on their well-being. Monkeys never undergo experimentation alone. They are always joined by their friends and siblings. They are given many playthings, such as food jigsaw puzzles and materials that they can tear to pieces.